KR20240045318A - Showerhead-pedestal gap measurement using differential capacitive sensor substrate - Google Patents

Abstract

A sensor disk configured to measure a gap between a first structure and a second structure in a processing chamber of a substrate processing system is configured to generate a first measurement signal indicative of a first distance between the top surface, the top surface of the sensor disk, and the first structure. At least one first capacitive sensor arranged on the upper surface of the configured sensor disk, the lower surface, and a second measurement signal indicative of a second distance between the lower surface of the sensor disk and the second structure. and at least one second capacitive sensor disposed on the lower surface of the sensor disk configured to produce.

Description

Showerhead-pedestal gap measurement using differential capacitive sensor substrate

This disclosure relates to test boards for substrate processing systems, and more particularly to test boards containing capacitive sensors.

The background description provided herein is intended to generally present the context of the disclosure. The work of the inventors named herein to the extent described in this Background section, as well as aspects of the subject matter that may not otherwise be recognized as prior art at the time of filing, are acknowledged, either explicitly or implicitly, as prior art to the present disclosure. It doesn't work.

Substrate processing systems are used to perform processes such as deposition and etching of films on substrates, such as semiconductor wafers. For example, deposition may include chemical vapor deposition (CVD), plasma enhanced CVD (PECVD), atomic layer deposition (ALD), and plasma enhanced ALD (PEALD). ) and/or other deposition processes may be performed to deposit a conductive film, dielectric film, or other types of film. During deposition, a substrate is arranged on a substrate support (e.g., a pedestal) and one or more precursor gases are delivered to the processing chamber using a gas distribution device (e.g., a showerhead) during one or more process steps. may be supplied. In the PECVD or PEALD process, plasma is used to activate chemical reactions within the processing chamber during deposition.

Cross-reference to related applications

This application claims the benefit of U.S. Provisional Patent Application No. 63/233,516, filed August 16, 2021. The entire disclosure of the above-referenced applications is incorporated herein by reference.

A sensor disk configured to measure a gap between a first structure and a second structure in a processing chamber of a substrate processing system is configured to generate a first measurement signal indicative of a first distance between the top surface, the top surface of the sensor disk, and the first structure. at least one first capacitive sensor arranged on the upper surface of the configured sensor disk, the lower surface, and configured to generate a second measurement signal indicative of a second distance between the lower surface of the sensor disk and the second structure. and at least one second capacitive sensor disposed on the lower surface of the sensor disk.

In other features, the at least one first capacitive sensor includes three capacitive sensors disposed on the upper surface of the sensor disk. The at least one second capacitive sensor includes three capacitive sensors disposed on the lower surface of the sensor disk. The at least one first capacitive sensor forms a first capacitor with the first structure and is configured to generate a first measurement signal based on a first capacitance of the first capacitor. The at least one second capacitive sensor forms a second capacitor with the second structure and is configured to generate a second measurement signal based on a second capacitance of the second capacitor. The sensor disk further includes a recessed area defined in the lower surface of the sensor disk. The recessed area extends from the outer edge of the sensor disk to the central area.

In other features, the system includes a sensor disk and receives a first measurement signal and a second measurement signal and determines the width of the gap between the first structure and the second structure based on the first measurement signal and the second measurement signal. It further includes a controller configured to calculate. The controller is configured to calculate the width of the gap based on the first distance, the second distance, and the thickness of the sensor disk. The controller correlates the first capacitance formed between the at least one first capacitive sensor and the first structure to the first distance and correlates the second capacitance formed between the at least one second capacitive sensor and the second structure to the second distance. and configured to calculate the width of the gap further based on the correlating stored data. The first structure is a showerhead and the second structure is a pedestal.

A system configured to measure a gap between a first structure and a second structure in a processing chamber of a substrate processing system includes at least one first capacitive sensor disposed on an upper surface of a sensor disk and a first capacitive sensor disposed on a lower surface of the sensor disk. A sensor disc comprising at least one second capacitive sensor and a controller, wherein the controller makes a first measurement indicative of a first distance between the upper surface of the sensor disc and the first structure, from the at least one first capacitive sensor. receive a signal, and receive, from at least one second capacitive sensor, a second measurement signal indicative of a second distance between the lower surface of the sensor disk and the second structure, and to the first measurement signal and the second measurement signal: It is configured to calculate the width of the gap between the first structure and the second structure based on the width of the gap between the first structure and the second structure.

In other features, the controller is configured to calculate the width of the gap based on the first distance, the second distance, and the thickness of the sensor disk. The controller correlates the first capacitance formed between the at least one first capacitive sensor and the first structure to the first distance and correlates the second capacitance formed between the at least one second capacitive sensor and the second structure to the second distance. and configured to calculate the width of the gap further based on the correlating stored data. The recessed area is defined in the lower surface of the sensor disc, and the recessed area extends from the outer edge of the sensor disc to the central area. The system further includes a mechanical indexer including an end effector, and the recessed area is configured to receive the end effector.

A method for measuring the gap between a first structure and a second structure in a processing chamber of a substrate processing system includes placing a sensor disk on an end effector, positioning the sensor disk in the gap between the first structure and the second structure. determining, using the sensor disk, a first distance between the upper surface of the sensor disk and the first structure and a second distance between the lower surface of the sensor disk and the second structure, and the first distance and the second distance. and calculating the width of the gap between the first structure and the second structure based on .

In other features, the sensor disk includes at least one first capacitive sensor disposed on an upper surface of the sensor disk and at least one second capacitive sensor disposed on a lower surface of the sensor disk. The method includes generating, using at least one first capacitive sensor, a first measurement signal indicative of a first distance between the upper surface of the sensor disk and the first structure, using at least one second capacitive sensor. , generating a second measurement signal indicative of a second distance between the lower surface of the sensor disk and the second structure, and generating a second measurement signal between the first structure and the second structure based on the first measurement signal, the second measurement signal, and the thickness of the sensor disk. It further includes calculating the width of the gap between the two structures.

In other features, the method includes generating a first measurement signal based on a first capacitance formed between at least one first capacitive sensor and the first structure and at least one second capacitive sensor and the second structure. It further includes generating a second measurement signal based on the second capacitance formed in . The sensor disc includes a recessed area defined in a lower surface of the sensor disc, the recessed area extending from an outer edge of the sensor disc to a central area, and positioning the sensor disc on the end effector comprises: and placing a recessed area of the sensor disk on the sensor disk. Positioning the sensor disk includes positioning the sensor disk at a midpoint between the first structure and the second structure. The first structure is a showerhead and the second structure is a pedestal.

Additional areas of applicability of the present disclosure will become apparent from the detailed description, claims and drawings. The detailed description and specific examples are intended for illustrative purposes only and are not intended to limit the scope of the disclosure.

The present disclosure will be more fully understood from the detailed description and accompanying drawings.
1 is a functional block diagram of one embodiment of a substrate processing system according to the present disclosure.
Figure 2a is an example of a sensor disk according to the present disclosure.
Figure 2b is an isometric view of the top surface of the sensor disk of Figure 2a.
Figure 2C is an isometric view of the lower surface of the sensor disk of Figure 2A.
Figure 2d is another example of a sensor disk according to the present disclosure.
Figure 3 is an example of a method for determining the distance between a showerhead and a pedestal using a sensor disk according to the present disclosure.
In the drawings, reference numbers may be reused to identify similar and/or identical elements.

A gap is defined between the lower surface of the gas distribution device (eg, showerhead) and the upper surface of the substrate support (eg, pedestal). Substrate processing parameters (eg, deposition rates, plasma profile, etc.) may vary based on the characteristics of the gap. Gap characteristics that may affect processing parameters include the width of the gap (i.e., the vertical distance between the showerhead and the substrate support) and variations in width in the horizontal direction (e.g., the tilted showerhead or substrate support surface). changes caused by ).

Various methods may be used to measure the gap. The showerhead and substrate may be adjusted based on the measurements to achieve the desired gap width and orientation. For example, showerhead tilt (i.e., level) and height and substrate support height may be adjustable. In some embodiments, a sensor disk or wafer may be arranged on a substrate support. One or more capacitive sensors are disposed on the upper surface of the sensor disk (ie, on the showerhead-facing surface of the sensor disk).

Capacitive sensors are configured to measure the distance between the upper surface of the sensor disk and the showerhead. For example, as distance changes, the capacitance detected by capacitive sensors changes. Capacitive sensors generate measurement signals indicative of capacitance and corresponding distance, which may then be used to determine the width of the gap. Capacitive sensors may be calibrated according to a known distance (eg, a known distance for a given material). As the distance between the capacitive sensors and the showerhead increases, the accuracy of the measurement signals decreases. For example, the accuracy of measurement signals may experience exponential decay with distance.

A sensor disk or substrate according to some embodiments of the present disclosure includes sensors, such as capacitive sensors, on both the top (i.e., showerhead-facing) surface and the bottom (i.e., substrate support-facing) surface. The sensor disk is positioned between the upper surface or other structure of the processing chamber (e.g., a gas distribution device, such as a showerhead) and the substrate support (e.g., a spindle, robot arm, etc.) without contacting the showerhead or substrate support. is positioned (on the end effector). For example, the sensor disk may be positioned and suspended at the midpoint between the showerhead and the substrate support.

Accordingly, the sensors disposed on the upper surface of the sensor disk are configured to measure the first distance between the sensor disk and the showerhead, while the capacitive sensors disposed on the lower surface of the sensor disk are configured to measure the first distance between the sensor disk and the substrate support. and configured to measure a second distance. The sum of the first distance, the second distance, and the thickness of the sensor disk corresponds to the measured width of the gap between the showerhead and the substrate support. At least one of the tilt (i.e., level) of the showerhead, the height of the showerhead, and the height of the substrate support can be adjusted based on the measured width of the gap.

Referring now to FIG. 1, an example of a substrate processing system 100 in accordance with the principles of the present disclosure is shown. Although the above-described example relates to plasma enhanced chemical vapor deposition (PECVD) systems, other plasma-based substrate processing chambers may be used. Substrate processing system 100 includes a processing chamber 104 that encloses other components of substrate processing system 100 . Substrate processing system 100 includes a substrate support, such as a pedestal 112 that includes an upper electrode 108 and a lower electrode 116. A substrate (not shown) is placed on the pedestal 112 between the top electrode 108 and the bottom electrode 116 during processing. Although described below with respect to a single processing chamber 104 and pedestal 112, the principles of the present disclosure apply to processing chambers that include a plurality of processing stations and pedestals, such as a quad station module (QSM) and It may also be implemented in systems including a plurality of processing chambers.

By way of example only, upper electrode 108 may include a showerhead 124 that introduces and distributes process gases. Alternatively, the top electrode 108 may include a conductive plate and the process gases may be introduced in another manner. In some examples, lower electrode 116 may correspond to a conductive electrode embedded within a non-conductive pedestal. Alternatively, pedestal 112 may include an electrostatic chuck that includes a conductive plate that serves as lower electrode 116.

A radio frequency (RF) generation system 126 generates and outputs an RF voltage to the upper electrode 108 and/or lower electrode 116 when plasma is used. In some examples, one of the upper electrode 108 and the lower electrode 116 may be DC grounded, AC grounded, or may be at a floating potential. By way of example only, RF generation system 126 may generate RF voltages that are fed to lower electrode 116 and/or upper electrode 108 by one or more matching and distribution networks 130. One or more RF voltage generators 128, such as voltage generator 128 (e.g., a capacitively-coupled plasma RF power generator, bias RF power generator, and/or other RF power generator ) may also include. For example, as shown, RF generator 128 provides RF and/or bias voltage to lower electrode 116. Lower electrode 116 may alternatively or additionally receive power from other power sources, such as power source 132 . In another example, RF voltage may be supplied to top electrode 108 or top electrode 108 may be connected to a ground reference.

The exemplary gas delivery system 140 includes one or more gas sources 144-1, 144-2, ..., and 144-N (collectively gas sources 144), where N is greater than zero. It is a larger integer. Gas sources 144 supply one or more gases (eg, precursors, inert gases, etc.) and mixtures thereof. Vaporized precursors may also be used. At least one of the gas sources 144 may include gases (eg, NH ₃ , N ₂ , etc.) used in the pretreatment process of the present disclosure. Gas sources 144 include valves 148-1, 148-2, ..., and 148-N (collectively valves 148) and mass flow controllers (MFCs) 152- 1, 152-2, ..., and 152-N) (collectively, MFCs 152) are connected to the manifold 154. The output of manifold 154 is fed to processing chamber 104. For example only, the output of manifold 154 is fed to showerhead 124. In some examples, an optional ozone generator 156 may be provided between the MFCs 152 and the manifold 154. In some examples, substrate processing system 100 may include a liquid precursor delivery system 158. Liquid precursor delivery system 158 may be integrated within gas delivery system 140 as shown, or may be external to gas delivery system 140. Liquid precursor delivery system 158 is configured to provide precursors that are liquid and/or solid at room temperature via bubblers, direct liquid injection, vapor withdrawal, etc.

Heater 160 may be connected to a heater coil 162 disposed within pedestal 112 to heat pedestal 112. Heater 160 may be used to control the temperature of pedestal 112 and substrate.

A valve 164 and pump 168 may be used to evacuate the reactants from the processing chamber 104. Controller 172 may be used to control various components of substrate processing system 100. By way of example only, controller 172 may be used to control process gas, carrier gas and precursor gas, plasma striking and extinguishing, removal of reactants, monitoring chamber parameters, etc. Controller 172 may receive measurement signals indicative of process parameters, conditions within processing chamber 104, etc. through one or more sensors 174 disposed throughout substrate processing system 100.

The controller 172 according to the present disclosure is further configured to receive measurement signals from a sensor disk 178 disposed between the showerhead 124 and the pedestal 112. For example, sensor disk 178 is disposed on end effector 182, and end effector 182 positions sensor disk 178 in the gap between showerhead 124 and pedestal 112. Capacitive sensors 186 are disposed on opposing upper and lower surfaces of sensor disk 178. Capacitive sensors produce measurement signals based on capacitively sensed distances between sensor disk 178 and showerhead 124 and between sensor disk 178 and pedestal 112, as described in more detail below. Create. Although described with respect to the distance between the showerhead 124 and the pedestal 112, the principles of the present disclosure can also be applied to measuring the distance between the pedestal 112, the upper electrode, upper surfaces, and the like of the processing chamber 104. You can.

Referring now to FIGS. 2A, 2B, and 2C, one embodiment of a sensor disk 200 according to the present disclosure is shown positioned between a showerhead 204 and a pedestal 208. For example, sensor disk 200 is disposed on an end effector 212 configured to position sensor disk 200 within one or more processing stations 216. For example, the end effector 212 may have a spindle of a mechanical indexer 224 configured to raise and lower the end effector 212 and rotate the end effector 212 between two or more of the processing stations 216. It may also be coupled to (220). Mechanical indexer 224 may correspond to a mechanical indexer configured to transfer a substrate between different processing stations within a processing chamber or process module (e.g., a multi-station module).

Sensors 228-1 and 228-2 (collectively referred to as sensors 228) are disposed on the upper surface 232 and lower surface 236, respectively, of the sensor disk 200. Sensors 228 include respective sensor electrodes. For example, sensor electrodes are made of highly conductive materials such as copper. In some embodiments, sensor electrodes may include a non-conductive coating to prevent corrosion, oxidation, etc. Although each of the sensors 228 is shown as including three sensor electrodes, in other embodiments the sensors 228 may include fewer or more sensor electrodes. The spacing and respective sizes of the sensor electrodes may also vary. For example, increasing the overall area occupied by sensors 228 (e.g., increasing the diameters of the sensor electrodes) may result in better sensitivity for detection of gaps and tilting.

Figure 2B shows an isometric view of the top surface 232, while Figure 2C shows an isometric view of the bottom surface 236. Although sensors 228 are described herein as capacitive sensors, sensors 228 may be implemented with other suitable types of proximity sensors, such as laser sensors, infrared sensors, etc. Sensors 228 generate measurement signals 240 (e.g. For example, one or more first measurement signals from sensors 228-1 and one or more second measurement signals from sensors 228-2.

As shown three sensors 228 are disposed on each side of the sensor disk 200, but in other embodiments there may be fewer (e.g. 1 or 2) or more (e.g. Four or more) sensors 228 may be provided on each side. For example, as the number of sensors 228 increases, the distance between the showerhead 204 and the pedestal 208, the tilt of the showerhead 204, etc. can be determined with increased accuracy.

For example, sensor disk 200 is positioned in gap G between showerhead 204 and pedestal 208. Sensors 228-1 are configured to generate measurement signals 240 based on the distance between the upper surface 232 of sensor disk 200 and the showerhead 204 (e.g., the width of gap g1). It is composed. That is, the sensors 228-1 are facing upward. Conversely, sensors 228-2 are configured to generate measurement signals 240 based on the distance between lower surface 236 and pedestal 208 (e.g., width of gap g2). That is, sensors 228-2 are facing downward.

Accordingly, the width of gap G corresponds to the sum of the widths of gap g1 and gap g2 and the thickness t of sensor disk 200 (including the thickness of sensors 228-1 and 228-2) (i.e., G = g1 + g2 + t). 2A, sensors 228-1 and 228 are shown projecting upwardly and downwardly from sensor disk 200, respectively, but in embodiments, sensors 228 have surfaces of sensors 228 protruding from sensor disk 200. It may be embedded within the sensor disk 200 so that it is coplanar (i.e., flush) with the surfaces of 200 . Accordingly, in different embodiments, the thickness t is the distance between the upper surface 232 and the lower surface 236 of the sensor disk 200 (i.e., the thickness of the substrate of the sensor disk 200), the sensors 228-1 and 228-2), the thickness of the sensor disk 200, etc.

Sensors 228 generate measurement signals 240 based on capacitance that varies based on the widths of gap g1 and gap g2. For example, each of the sensors 228 may transmit a reference signal (e.g., a reference signal (e.g., may be configured to generate an excitation signal having a sinusoidal waveform, a square waveform, etc. As a result, a capacitor is formed between the sensor 228 and the surfaces of each of the showerhead 204 and pedestal 208. The capacitance of the capacitor as measured by each sensor 228 represents the distance between the capacitive sensor and the corresponding surface of the showerhead 204 or pedestal 208. That is, the capacitances of the capacitive sensors 228-1 represent respective distances between the capacitive sensors 228-1 and corresponding portions of the showerhead 204. Conversely, the capacitances of capacitive sensors 228-2 represent respective distances between capacitive sensors 228-2 and corresponding portions of pedestal 208.

Accordingly, the measurement signals 240 represent the capacitances of the sensors 228, which in turn represent the distances between each of the sensors and respective portions of the showerhead 204 or pedestal 208. For example, measurement signals 240 may include digital values or analog values of respective capacitances. In one embodiment, sensors 228 measure variable resistance or reactance indicative of capacitance, determine capacitance based on the measured variable resistance or reactance, and measure a respective signal indicative of capacitance (measurement signals 240). (as) is configured to output a digital value.

In some embodiments, measurement signals 240 are provided to a communication interface, such as wireless interface 244. Wireless interface 244 transmits measurement signals 240 (i.e., as wireless signals 248 containing a digital value representing capacitance) to a device external to processing station 216, such as controller 252. For example, controller 252 corresponds to controller 172 in FIG. 1 . In some embodiments, wireless interface 244 may transmit measured signals 240 to controller 252 in real time or near real time. In other embodiments, sensor disk 200 includes a memory configured to store measurement data corresponding to measurement signals 240 that may be retrieved when sensor disk 200 is removed from processing station 216. It may also include . In some embodiments, wireless interface 244 transmits measurement data in batches (e.g., in a 4-station chamber, wireless interface 244 transmits measurement data to all 4 stations before transmitting it to controller 252). It may wait until several stations are measured) or it may interact with memory to transmit periodically (i.e., after a set amount of time has elapsed). As shown in FIG. 2B, sensor disk 200 may include one or more batteries 256. Battery 256 provides power to sensors 228 and wireless interface 244. Batch or periodic transmissions may reduce power consumption of wireless interface 244.

Accordingly, sensor disk 200 is configured to determine the width of gap G without being handed off to (i.e., placed on) pedestal 208. Additionally, the sensor disk 200 can be rotated through a plurality of processing stations to measure individual gaps while remaining on the end effector 212, reducing the amount of time needed to measure the gaps and allowing the end effector (212) to reducing particle generation associated with handoffs between 212) and pedestal 208, etc.

Additionally, because sensor disk 200 remains on end effector 212, the required clearance between sensor disk 200, showerhead 204 and pedestal 208 may be reduced. That is, because the end effector 212 does not place the sensor disk 200 on the pedestal 208, the end effector 212 does not need to be lowered and removed from the processing station 216 during the measurement. Accordingly, the thickness of the sensor disk 200 containing the sensors 228 is adjusted to reduce the distance between the sensors 228 and the surfaces of the showerhead 204 and the pedestal 208 (e.g., 10 mm or more) can be increased.

For example, for a gap G of approximately 17.0 mm (e.g., within 10% of 17.0 mm) and a thickness t of sensor disk 200 of approximately 11.0 mm (e.g., within 10% of 11.0 mm), Gap g1 and gap g2 may each be reduced to approximately 3.0 mm (eg, within 10% of 3.0 mm). Likewise, for gap G of less than 20.0 mm, the thickness t of sensor disk 200 may be at least 60% (e.g., 60% to 70%) of the width of gap G. As the width of gap G increases, the thickness t of sensor disk 200 may be increased to maintain gap g1 and gap g2 relatively small (e.g., less than 5.0 mm, less than or equal to 3 mm, etc.). The accuracy of sensors 228 (i.e., the accuracy of the relationship between capacitance and distance) is inversely proportional to distance and increases exponentially as distance decreases. Accordingly, increasing the thickness t increases the accuracy of measurement signals 240.

In some embodiments, lower surface 236 is flat (e.g., planar) and supported on end effector 212. In other embodiments, as shown in FIG. 2C, lower surface 236 includes a recessed area or socket 260 configured to receive end effector 212. That is, the shape of the recessed area 260 is configured to accommodate the end effector 212 such that the end effector 212 is recessed within the lower surface 236 of the sensor disk 200. For example, recessed area 260 extends from the outer edge of sensor disk 200 to the central area. When the sensor disk 200 is supported on the end effector 212, the lower surface 264 of the end effector 212 is flush with the lower surface 236 of the sensor disk 200 (as shown). (i.e., on the same plane) or slightly above or below the lower surface 236 (e.g., 0 to 1.5 mm). In this manner, the end effector 212 connects the showerhead 204 and pedestal 208 such that gap g1 and gap g2 are approximately the same (e.g., within 5% of each other) regardless of the thickness t of sensor disk 200. The sensor disk 200 can be more easily positioned at the midpoint between the two sides.

In some embodiments, pedestal 208 (or the top surface of pedestal 208) may be comprised of a non-metal, such as ceramic. Accordingly, the top surface of pedestal 208 may not be configured to form a capacitor with sensors 228-2. In these embodiments, a metal plate, ring, or other structure (e.g., shown in FIG. 2A as metal disk 268) has a metallic surface that can be detected by sensors 228-2. It may be selectably placed on the pedestal 208 to provide. For example, metal disk 268 includes the same material as showerhead 204 such that equal distances correspond to substantially equal capacitances. Calculation of gap g2 may include taking into account (e.g., adding) a known thickness of metal disk 268. In other embodiments, a metal disk 268 may be placed on the pedestal 208 to reduce the gap g2 and increase the accuracy of capacitive sensing.

In another embodiment shown in Figure 2D, sensor disk 200 includes an upper disk 200-1 and a lower disk 200-2 (collectively referred to as sensor disk 200). Sensors 228-1 are disposed on or within the upper surface of upper disk 200-1. Conversely, sensors 228-2 are disposed on or within the lower surface of lower disk 200-2. Upper disk 200-1 and lower disk 200-2 are coupled together (eg, using a plurality of posts 272) to define a gap 276. End effector 212 is inserted into gap 276 to retrieve, support, and transport sensor disk 200. In this way, sensor disk 200 can be configured to minimize gap g1 and gap g2. For example, the thicknesses of upper disk 200-1 and lower disk 200-2 may be increased to reduce gap g1 and gap g2.

As described above, sensor disk 200 includes sensors 228 on both the top surface and the bottom surface, but in another embodiment sensor disk 200 only has sensors 228 on one surface (e.g., the top surface or the bottom surface). (only on the bottom surface). In this embodiment, the sensor disk 200 is first positioned in a first orientation (i.e. in a first direction, for example with the sensor 228 facing upward towards the showerhead 204) to measure the first gap g1. together) may be disposed on the end effector 212. The sensor disk 200 is then placed in a second orientation (i.e., flipped over) such that the sensor 228 faces in the opposite, second direction (i.e., downward toward the pedestal 208) to measure the second gap g2. (flip)) You can also.

3 shows a first structure (e.g., an upper surface of a processing chamber, a showerhead, such as showerhead 204, etc.) using a sensor disk (e.g., sensor disk 200) according to the present disclosure. This is one embodiment of a method 300 of determining a distance between a second structure (e.g., a lower surface of a processing chamber, a pedestal such as pedestal 208, etc.). At 302, method 300 (e.g., controller 252) performs a calibration process to generate and store calibration data correlating measured capacitances with distances between sensors 228 and respective surfaces. Perform. For example, the calibration process may be performed at a processing station that includes showerhead 204 and pedestal 208, etc., composed of the same materials and disposed at a known distance. In this way, method 300 stores data correlating measured capacitances determined by sensors 228 with actual distances between sensors 228 and respective surfaces of the showerhead and pedestal.

At 304, sensor disk 200 is transferred to mechanical indexer 224 (e.g., on end effector 212). For example, sensor disk 200 is handed off from a transfer robot to end effector 212 at a loading station in a multi-station process module. At 308, the end effector 212 positions the sensor disk 200 between the showerhead and the pedestal at the first processing station. In some embodiments, the first processing station is a loading station. In other embodiments, mechanical indexer 224 rotates to position sensor disk 200 at a processing station different from the loading station.

At 312, method 300 (e.g., mechanical indexer 224 in response to controller 252) positions sensor disk 200 at a predetermined position between the showerhead and the loading station. By way of example only, the predetermined position is the midpoint between the showerhead and the loading station (i.e. the midpoint position). For example, mechanical indexer 224 is configured to raise and lower end effector 212 to adjust the vertical position of sensor disk 200. Method 300 (e.g., controller 252) determines the midpoint based on the relative capacitances of sensors 228-1 and 228-2 at different vertical positions.

In one embodiment, mechanical indexer 224 adjusts sensor disk 200 through different positions (e.g., from the lowest position to the highest position or vice versa) and controls sensors 228-1 at different positions. and 228-2) are measured. In the lowest position, the capacitances of sensors 228-2 will be larger (representing a relatively smaller distance to the pedestal), while the capacitances of sensors 228-1 will be lower (representing a relatively smaller distance to the showerhead). indicates a greater distance). Conversely, in the top position, the capacitances of sensors 228-2 will be lower (representing a relatively greater distance to the pedestal), while the capacitances of sensors 228-1 will be larger (representing a relatively greater distance to the showerhead). represents a relatively smaller distance).

At each of the positions, method 300 measures the capacitances of sensors 228-1 (e.g., the average capacitance of two or more of sensors 228-1) and the capacitances of sensors 228-2. Determine the difference between (e.g., the average capacitance of two or more of the sensors 228-2). The position corresponding to the smallest difference between the capacitances of sensors 228-1 and 228-2 corresponds to the midpoint between the showerhead and the pedestal (e.g., if the materials of the surfaces of the showerhead and pedestal are the same) assuming it does). That is, method 300 allows the sensors ( It may be assumed that the capacitances measured by 228-1 and 228-2) will be substantially the same.

At 316, method 300 measures the capacitances of each of sensors 228-1 and 228-2 (e.g., using sensor disk 200 at a predetermined position, such as the midpoint position). do. For example, as described above, sensors 228 generate measurement signals 240 representing measured capacitances that are transmitted as digital values to controller 252. At 320, method 300 (e.g., controller 252) calculates distances (e.g., widths of gap G) between respective portions of the showerhead and pedestal based on the capacitances. do. For example, controller 252 calculates distances based on the measured capacitances and stored calibration data that correlates the capacitance to the distance for each of the sensors 228. Controller 252 may store the calculated distances for recall, display, etc.

As described, the method 300 determines distances with the sensor disk 200 at the midpoint position, but in other embodiments, the midpoint position is not determined, but the sensor is at positions other than the midpoint position, etc. Using disk 200, capacitances and distances can be determined. For example, the mechanical indexer 224 maintains the same nominal or calibrated position during the process and the distance between each showerhead and the pedestals without adjusting the vertical position of the sensor disk 200. The sensor disk 200 may be rotated through a plurality of processing stations to measure the sensors.

At 322, a showerhead and/or pedestal of one or more of the processing stations may be selectively adjusted based on the measured gap G. The measured gap G may indicate that the showerhead is tilted, that the distance between the showerhead and the pedestal is larger or smaller than the target distance, etc. In some embodiments, coordination is performed manually (e.g., by accessing the internals of a process module during servicing). In other embodiments, the adjustment may be performed automatically by raising or lowering one or both the showerhead and pedestal using respective actuators in response to controller 252. Adjustments may be performed iteratively until the measured gap corresponds to the desired gap. For example, method 300 may repeat 316, 320, and 322 until the desired gap is achieved.

At 324, method 300 determines whether to measure gap G for another processing station. If true, method 300 continues with 328. If false, method 300 continues with 332. At 328, method 300 (e.g., mechanical indexer 224) rotates end effector 212 to position sensor disk 200 at another processing station and continues with 312.

At 332, sensor disk 200 is withdrawn from mechanical indexer 224. For example, sensor disk 200 is returned to a loading station and retrieved using a transfer robot. The sensor disk 200 is stored within a substrate processing system (e.g., in a vacuum transfer module or a buffer station within an equipment front end module), retrieved from the substrate processing system, and transferred to another multi-station module. It may be transferred to . One or more steps of method 300 may be omitted or rearranged while still achieving the purpose of determining the distance between a showerhead (e.g., showerhead 204) and a pedestal (e.g., pedestal 208). there is. For example, calibration step 302 may be omitted in some events.

The foregoing description is merely illustrative in nature and is not intended to limit this disclosure, its application examples, or its uses in any way. The broad teachings of this disclosure may be implemented in various forms. Accordingly, although the disclosure includes specific examples, the true scope of the disclosure should not be so limited as other modifications will become apparent upon study of the drawings, specification, and claims below. It should be understood that one or more steps of the method may be performed in a different order (or simultaneously) without changing the principles of the disclosure. Additionally, although each of the embodiments has been described above as having specific features, any one or more of these features described for any embodiment of the present disclosure may be used in any other embodiment, even if the combination is not explicitly described. It may be implemented with the features of the examples and/or in combination with the features of any other embodiments. That is, the described embodiments are not mutually exclusive, and substitutions of one or more embodiments with other embodiments remain within the scope of the present disclosure.

Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are defined as “connected,” “engaged,” “coupled ( coupled", "adjacent", "next to", "on top of", "above", "below", and "placed It is described using various terms, including “disposed”. Unless explicitly described as “direct,” when a relationship between a first element and a second element is described in the above disclosure, this relationship is defined as one in which no other intermediary elements exist between the first and second elements. It may be a direct relationship, but it may also be an indirect relationship where one or more intermediary elements (spatially or functionally) exist between the first element and the second element. As used herein, at least one of the phrases A, B and C should be interpreted to mean logically (A or B or C), using the non-exclusive logical OR, and "at least one of A, It should not be interpreted to mean “at least one B and at least one C.”

In some implementations, a controller is part of a system that may be part of the examples described above. These systems may include semiconductor processing equipment, including a processing tool or tools, a chamber or chambers, a platform or platforms for processing, and/or specific processing components (wafer pedestal, gas flow system, etc.). These systems may be integrated with electronics to control their operation before, during, and after processing of the semiconductor wafer or substrate. An electronic device may be referred to as a “controller” that may control a system or various components or subparts of systems. The controller may control delivery of processing gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, radio frequency (e.g., heating and/or cooling), depending on the processing requirements and/or type of system. RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and motion settings, load locks connected or interfaced to the tool and other transfer tools and/or specific system. It may be programmed to control any of the processes disclosed herein, including wafer transfers to a furnace.

Generally speaking, a controller includes various integrated circuits, logic, memory and/or components that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, etc. It may also be defined as an electronic device with software. Integrated circuits include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and/or program instructions (e.g., software). It may also include one or more microprocessors or microcontrollers that execute. Program instructions may be instructions that communicate with a controller or with a system in the form of various individual settings (or program files) that specify operating parameters for performing a particular process on or for a semiconductor wafer. In some embodiments, operating parameters may be used by process engineers to achieve one or more processing steps during fabrication of dies of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits and/or wafers. It may be part of a recipe prescribed by .

The controller may, in some implementations, be coupled to or part of a computer that may be integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be all or part of a fab host computer system or within the “cloud” that may enable remote access of wafer processing. The computer may monitor the current progress of manufacturing operations, examine the history of past manufacturing operations, examine trends or performance metrics from multiple manufacturing operations, change parameters of current processing, or perform processing steps following current processing. It may also enable remote access to the system to configure or start new processes. In some examples, a remote computer (eg, a server) may provide process recipes to the system over a network, which may include a local network or the Internet. The remote computer may include a user interface that allows entry or programming of parameters and/or settings that are later transferred to the system from the remote computer. In some examples, the controller receives instructions in the form of data that specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of tool the controller is configured to control or interface with and the type of process to be performed. Accordingly, as described above, a controller may be distributed, including one or more discrete controllers networked and operating together toward a common purpose, such as the processes and controls described herein. An example of a distributed controller for these purposes would be one or more integrated circuits on a chamber in communication with one or more remotely located integrated circuits (e.g. at a platform level or as part of a remote computer) that combine to control the process on the chamber. .

Without limitation, example systems include plasma etch chambers or modules, deposition chambers or modules, spin-rinse chambers or modules, metal plating chambers or modules, clean chambers or modules, bevel edge etch chambers or modules, and physical vapor etch chambers or modules. physical vapor deposition (PVD) chamber or module, chemical vapor deposition (CVD) chamber or module, atomic layer deposition (ALD) chamber or module, atomic layer etch (ALE) It may include a chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be used or associated in the fabrication and/or fabrication of semiconductor wafers.

As noted above, depending on the process step or steps to be performed by the tool, the controller may be configured to: used in one or more of the following: other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a main computer, another controller, or tools. You can also communicate with.

Claims (22)

A sensor disk configured to measure a gap between a first structure and a second structure in a processing chamber of a substrate processing system, comprising:
upper surface;
At least one first capacitive sensor arranged on the upper surface of a sensor disk, wherein the at least one first capacitive sensor is positioned in a first structure between the upper surface of the sensor disk and the first structure. 1 the at least one first capacitive sensor configured to generate a first measurement signal indicative of a distance;
lower surface; and
at least one second capacitive sensor disposed on the lower surface of the sensor disk, wherein the at least one second capacitive sensor is indicative of a second distance between the lower surface of the sensor disk and the second structure. 2. A sensor disk comprising the at least one second capacitive sensor configured to generate a measurement signal. According to claim 1,
The at least one first capacitive sensor includes three capacitive sensors disposed on the upper surface of the sensor disk. According to claim 1,
The at least one second capacitive sensor comprises three capacitive sensors disposed on the lower surface of the sensor disk. According to claim 1,
The at least one first capacitive sensor is configured to (i) form a first capacitor with the first structure and (ii) generate the first measurement signal based on a first capacitance of the first capacitor. , sensor disk. According to claim 4,
The at least one second capacitive sensor is configured to (i) form a second capacitor with the second structure and (ii) generate the second measurement signal based on a second capacitance of the second capacitor. , sensor disk. According to claim 1,
A sensor disc further comprising a recessed area defined in the lower surface of the sensor disc, the recessed area extending from an outer edge of the sensor disc to a central area. Comprising the sensor disk of claim 1 and (i) receiving the first measurement signal and the second measurement signal, and (ii) comprising the first structure based on the first measurement signal and the second measurement signal. The system further comprising a controller configured to calculate the width of the gap between the second structures. According to claim 7,
and the controller is configured to calculate the width of the gap based on the first distance, the second distance, and the thickness of the sensor disk. According to claim 8,
The controller is configured to (i) correlate a first capacitance formed between the at least one first capacitive sensor and the first structure to the first distance and (ii) determine the at least one second capacitive sensor and the second structure. and calculate the width of the gap further based on stored data correlating a second capacitance formed between structures to the second distance. According to claim 1,
The sensor disk of claim 1, wherein the first structure is a showerhead and the second structure is a pedestal. A system configured to measure a gap between a first structure and a second structure in a processing chamber of a substrate processing system, comprising:
a sensor disk comprising at least one first capacitive sensor disposed on an upper surface of the sensor disk and at least one second capacitive sensor disposed on a lower surface of the sensor disk; and
A controller comprising:
receive, from the at least one first capacitive sensor, a first measurement signal indicative of a first distance between the upper surface of the sensor disk and the first structure;
receive, from the at least one second capacitive sensor, a second measurement signal indicative of a second distance between the lower surface of the sensor disk and the second structure; and
The system is configured to calculate the width of the gap between the first structure and the second structure based on the first measurement signal and the second measurement signal. According to claim 11,
and the controller is configured to calculate the width of the gap based on the first distance, the second distance, and the thickness of the sensor disk. According to claim 12,
The controller is configured to (i) correlate a first capacitance formed between the at least one first capacitive sensor and the first structure to the first distance and (ii) determine the at least one second capacitive sensor and the first structure. The system is configured to calculate the width of the gap further based on stored data correlating a second capacitance formed between two structures to the second distance. According to claim 11,
A recessed area is defined in the lower surface of the sensor disc, and the recessed area extends from an outer edge of the sensor disc to a central area. According to claim 14,
The system further comprising a mechanical indexer including an end effector, wherein the recessed region is configured to receive the end effector. A method for measuring a gap between a first structure and a second structure in a processing chamber of a substrate processing system, comprising:
Placing a sensor disk on the end effector;
positioning the sensor disk in the gap between the first structure and the second structure;
Using the sensor disk, determining (i) a first distance between the upper surface of the sensor disk and the first structure and (ii) a second distance between the lower surface of the sensor disk and the second structure. ; and
Calculating the width of the gap between the first structure and the second structure based on the first distance and the second distance. According to claim 16,
The method of claim 1 , wherein the sensor disk includes at least one first capacitive sensor disposed on an upper surface of the sensor disk and at least one second capacitive sensor disposed on a lower surface of the sensor disk. According to claim 17,
generating, using the at least one first capacitive sensor, a first measurement signal indicative of the first distance between the upper surface of the sensor disk and the first structure;
generating, using the at least one second capacitive sensor, a second measurement signal indicative of the second distance between the lower surface of the sensor disk and the second structure; and
Calculating the width of the gap between the first structure and the second structure based on the first measurement signal, the second measurement signal, and the thickness of the sensor disk. According to claim 18,
generating the first measurement signal based on a first capacitance formed between the at least one first capacitive sensor and the first structure; and
Generating the second measurement signal based on a second capacitance formed between the at least one second capacitive sensor and the second structure. According to claim 16,
The sensor disc includes a recessed area defined in the lower surface of the sensor disc, the recessed area extending from an outer edge of the sensor disc to a central area, and the sensor disc on the end effector. wherein positioning includes positioning the recessed area of the sensor disk on the end effector. According to claim 16,
Wherein positioning the sensor disk includes positioning the sensor disk at a midpoint between the first structure and the second structure. According to claim 16,
Wherein the first structure is a showerhead and the second structure is a pedestal.

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